1. Technical Field
This invention relates to a method of extracting solanesol. In particular, the invention provides a technique whereby the crude solanesol can be extracted by microwave-assisted from potato stems and/or leaves.
2. Background
Solanesol, a long-chain terpenoid alcohol, is the starting material for many high-value biochemicals, including Vitamin K analogues and co-enzyme Q10 which is useful in the treatment of heart diseases, cancers and ulcers. Co-enzyme Q10 is widely used in medicine field, health care field and cosmetic area. It present in virtually in every cell in the human body and is known as the “miracle nutrient”. It can be also used as anti-aging, treatment senile dementia and congenital anemia.
China patent CN 91103632.6 and CN 93118734.6 describe an extraction method of solanesol from discarded or moldy tobacco leaves. China patent CN 93118734.6 reports a preparation method of unsaponified solanesol. China patent CN 94102575.6 describes an extraction method and equipment of solanesol. China patent CN 94115570.6 reports a process for producing solanesol. China patent CN 99117334.1 describes a process for extracting solanesol. China patent CN 02134560.0 describes a solanesol complex and process for producing the same. China patent 200410013561.1 provides a process for extracting and purifying solanesol from potato leaves. A deep processing of tobacco concrete for producing tobacco absolute and solanesol: see China patent CN 01108703.X. China patent 200410053681.4 provides a process for clean preparation of high-purity solanesol. China patent 200410040400.1 describes a high-purity solanesol and synthesize for producing the same. Solanesol is extracted from potato leaves and then purifying the solanesol by crystallizing from an organic solvent. The purity of solanesol is higher than 90%, e.g. China patent CN 1762940A describes a process for extracting and purifying solanesol from potato and potato leaves, with organic solvent extraction and recrystallization, the purity of solanesol is higher than 90%.
There is large planting area of potato in Chinese rural. The yield of potato is almost 3 million tons in Dingxi area, Gansu province. However, about 550 thousands ton of potato leaves are not effectively utilized. There would be 1.375 thousands ton of solanesol if half of the leaves were used. The economic benefit is notable.
The most conventional method for extraction of solanesol from potato leaves is heat-reflux extraction with an organic solvent in which the solanesol is soluble. The disadvantages of the method are: time-consuming, high consumption of solvent, higher energy consumption and high cost.
Microwave energy penetrates materials and produces a volumetrically distributed heat source due to molecular friction resulting from dipolar rotation of polar solvents and from the conductive migration of dissolved ions. The highly localized temperature and pressure can cause selective migration of target compounds from the material to the extraction solvent at a more rapid rate and with similar or better recoveries compared with conventional heat-flux extraction.
So far, no literatures or patents refer to microwave-assistant extraction of solanesol from potato stems and/or leaves.